Copper-arsenic dust



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OI DELOBO, ONTARIO, CANADA,- ASSIGNOR 'I'O RICHES, rm &

. 1,642,511- OFFICE.-

\ co., A conronn'rxon'or NEW JERSEY.

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It Dawe Original "application area December 2a, aaafseri r No. 432,892. Divided and this .a' u- "cation flled migust 9,19%.Sena1" 1io.731,203.

This application is "a division of my 50- I prefer to allow the paste or semi-liquid pending application-filed Dec. 23,- 1920, Ser.

No. 432,692 and now issued Patent No 1,541,753 dated June 9,1925. 5 The" subject-matter of this invention is a dry dust-ing powder, suitable for an insecticide or fung c de or both.

Arsenic is recognized as a basis for insecticides. and copper, nickel, silver, zinc,

"aluminum, etc,- as more or less effective] fungicides. Dusting or the application of dry powdered insecticides. and fungicides has many advantages over-the applying of the same materials. suspended in liquids.

16 White arsenic is the base from which many agricultural insecticides aremad'e. The resent methods of manufacturing arsenica insecticides suitable for use on foliage conslst, for the most. part, of numerous costly wet processes. The invention set forth in this application reduces the cost ofmanufactur- \mg commercial dry, or powdered arsemcal compounds from white arsemc.

My method ofprocedure is asfollows:

a I mix together ground quicklime, white arsenic and water. Avery imperfect arsenite of lime is then formed by the-reaction of the lime and arsenic in the presence of water. I use apprgximately equal parts of quicklime andwhite arsenic, but the proportions may be varied widely. I prefer to use ground quicklime, combined with arsenic, on account of its low costand availaarsenite is produced. a Y

Copper-sulphate in the ordinary crystal form is then added to the mixture or-arsenical salt described. I prefer'to add an exces's'of copper sulphate ormore than is requlred to completely react with the arsenical salt. The .wateradded is varied according'to therequirments of the finished product. For instance, if a product for potatoes is desired, the material at this stage would be a thlck green paste. 'Other metallic salts of copper may be substituted or salts of aluminum, nickel, zinc, iron, cobalt and sllver', etc, will serve.

chemically combine, but in many cases this copper sulphate and the formation there? of a owdersuitable for dusting, thus avol ing t e use of costly oxidizing processes.

to stand for twenty-four hours in order to allow the metallic and the arsenical salts to is not essential.

I' then add the paste or semi-liquid-contalmn the metallic salt of arsenic to enough lquickllme so that the lime in hydrating takes or barium oxides may be substituted for the quicklime, but -I prefer to use quicklime on account of its low cost, quick reaction and availability.

I Artificial heat other than that produced by slaking .lime ,may be used at any time to accelerate the process but it is not necessary to a successful or suitable final product. ffn' certain cases the white arsenic may be mixedwith the metallic salt, and the two addedto the quicklime, either before or during the process of slaking, or the white arsenicmay be added to the quicklime either before or after the metallic salt, or at the end 'of the process. The activity of the' arsenic, both as regards safety and insecticidal value, may be thus varied asdesired.

The process describedand which I prefer to follow is mixing white arsenic, ground quicklime and'water, using only. suflicient water to-hydrate'the quicklime and form a paste, and the subsequent addition of copper sulphate crystals and the mixing of this mass with quicklime, which takes up the free water, resulting in the dehydration of the More .or less stirring duringjthe process is necesssary and hydrators, dough mixers or troughs with either hand ormechanicalstirrers may be used for the first, second and third operations.- Numerous types ofattrltion, beater and grinding mills are suitable for the final grinding.

I prefer tohave a small portion 'of the/105 lime remainin the oxide form, as it causes{.

the dust to keep longer without eaking. 7 What I claim and. desire to secure by Let Y ters Patent is A method fer m g c d the lime and form a paste, adding a soluble metallic salt having fungicidal value thereto and then adding lime sufliciently in excess to take up all free water. 7

3. A method for making a combined insecticide and fungicide in dry powder form, comprising first mixing together a soluble arsenic compound, lime and sufiicient water to hydrate the lime and form a paste, adding a soluble copper salt havin fungicidal value thereto and then adding lime sufficiently in excess to take up all free water.

4. A method for making a combined insecticide and fungicide in dry powder form, comprising first mixing together a soluble arsenic compound, lime and sufficient water to hydrate the lime and form a aste, adding copper sulphate thereto and t en adding lime sufiiciently in excess to take up all free water.

5. A method for making a combined insecticideand fungicide in ry powder form,

comprising first mixing together white arsenic, lime and sufficient water to hydrate the lime and form a paste, adding copper sulphate thereto and then adding lime sufliciently in excess to take up all free water. 6. A method of making a combined insecticide and fungicide in dry powder form,

comprising first making calcium arsenit in paste form, reacting copper'sulphate there with, the copper salt being in excess of the amount required to completely react with the arsenical salt, and adding suiiicient lime to take up all free water. i

7. The method of forming a powdered insecticide and fungicide suitable for dusting, comprising reacting white arsenic with a copper salt having fungicidal value, in the presence of slacking lime then addingmore lime thereto, the lime being in excess sulficient to take up all free water and produce the product in a dry powder form.

Signed at Medina in the county of Orleans and State of New York, this 6th day of August A.' D.V 1924. v

GEORGE E. SANDERS. 

